1890001 has 4 divisors (see below), whose sum is σ = 1892772. Its totient is φ = 1887232.

The previous prime is 1889999. The next prime is 1890019. The reversal of 1890001 is 1000981.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 389376 + 1500625 = 624^2 + 1225^2 .

It is a cyclic number.

It is not a de Polignac number, because 1890001 - 2¹ = 1889999 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1890041) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 441 + ... + 1993.

It is an arithmetic number, because the mean of its divisors is an integer number (473193).

2^1890001 is an apocalyptic number.

It is an amenable number.

1890001 is a deficient number, since it is larger than the sum of its proper divisors (2771).

1890001 is a wasteful number, since it uses less digits than its factorization.

1890001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2770.

The product of its (nonzero) digits is 72, while the sum is 19.

The square root of 1890001 is about 1374.7730721832. The cubic root of 1890001 is about 123.6385808000.

Adding to 1890001 its reverse (1000981), we get a palindrome (2890982).

The spelling of 1890001 in words is "one million, eight hundred ninety thousand, one".